Who's Winning the String Wars And Why Should You Care?
A conversation with theoretical physicist Peter Woit (Part II)
By Gerald Alper
I first encountered the name Peter Woit in a 2006 New Yorker article (Unstrung) by the resident all-purpose virtuoso critic Jim Holt. It was vintage Jim Holt: a velvet-gloved deconstruction of a currently fashionable (but not well substantiated) idea. Except this was no ordinary fashionable idea. It was the reigning paradigm (then and now) in fundamental physics — string theory. Repeatedly called “the best candidate for a theory of everything,” this was the heroic attempt to capture the elusive holy grail of contemporary physics: a theory of quantum gravity that could for the first time successfully unify the twin towers of Einstein’s Theory of General Relativity and quantum mechanics’ astonishingly successful standard model of particle physics.
But there is a problem. After more than thirty years of enlisting some of the best and brightest minds on the planet there is still not a shred of experimental evidence in support of the theory. There is not a single prediction that has been validated; not a single experimental design has been thought of, let alone been built, with a chance of succeeding. For the first time in history, according to Holt “theory has caught up to experiment.” The super collider that would be required, —at energy levels approximating those prevailing at the time of the Big Bang—is hopelessly out of reach.
Then why has the theory endured? Holt offers a number of reasons. Although it cannot be proved, neither can it be disproved. String theory, even its worst critics admit, contains magnificent mathematics. Its leader is Ed Witten of Princeton, who is widely acknowledged to be not only “the greatest theoretical physicist in the world,” but a mathematical genius of the highest rank. He is the first theoretical physicist in history to win (in 1990 for his work on knots) the prestigious Fields medal (awarded every four years and considered to be the Nobel Prize of mathematics).
String theory is based on a radical idea — that the ultimate constituents of matter are not point-like particles but almost infinitesimally tiny vibrating strands of energy, or strings, (Holt calls them “tiny rips in the fabric of space”) — that if true would revolutionize physics. When Witten decided to get on the string bandwagon, he went in big. Droves of physicists who hold him in awe, followed suit. Soon he was writing astonishing papers that were models of breathtaking clarity and startling profundity and are considered so today. In just a few years, thousands of papers on string theory were published and hundreds of PhDs were awarded. It became harder and harder and then impossible to get a job in physics departments unless you were a string theorist. This is the time (in the early 80s) when a joyous Ed Witten, flushed with success, would boast — at the conclusion of one of his early lectures to a gathered audience of typically dumbfounded Princeton physicists — “I have discovered a new theory of physics.” And this is the time when a triumphant Witten would utter perhaps his most famous pronouncement: “String theory is a piece of twenty first century mathematics which has fallen into our hands.”
But not everyone was enamored. The great Richard Feynman, never one to pull his punches, came down hard on string theory. It was “nonsense,” it was “crazy,” it was a virtual world cooked up by myopic mathematicians who had no intuitive feel for the way nature really works: “Whenever a parameter seems wrong, they arbitrarily change it to suit the theory.” To Harvard’s Nobel Laureate Sheldon Glashow, string theory was “a new version of medieval theology.” To Roger Penrose, one of the greatest mathematical astrophysicists of the past one hundred years, string theory was a disturbing, wildly speculative program: “When they started to talk about extra hidden dimensions is when I parted company with string theory.”
In spite of which, the hold that string theory had on the zeitgeist of the physics community would only tighten. In the mid-nineties, Ed Witten proved once again that he was string theory’s preeminent magician. He would show, dramatically, that what was believed to be five separate, competing theories was really one theory. He called it M theory, for matrix, for mother, for mystery. Only time will tell what M theory would stand for. What is important to know is that M theory is the über theory. As the nineties rolled on — and still not a shred of experimental proof — the chorus of discontent grew steadily more strident. In 1996 the provocateur, science writer par excellence John Horgan wrote a daring, challenging book: The End of Science. Based on decades worth of probing interviews of world class scientists, he advanced a startling, bare-bones thesis: with the establishment of the Big Bang paradigm in 1965 science, so far as Big Ideas are concerned, had exhausted itself! It was just “bumping up against reality.” In the ensuing thirty years, theoretical physicists have not come up with a single new idea. They were just filling in the details. So confident and cocky was John Horgan that he would put his money where his mouth was. He would wager a not inconsiderable amount of money that in the ensuing thirty years there would not be a single Nobel Prize awarded to a string theorist (a bet he has yet to pay off). The End of Science struck a nerve, was one of the most widely discussed science books in years, and would go on to sell over two hundred thousand copies – but the landscape of physics hardly took notice.
Attention would be paid, however, when Steven Weinberg, in a brilliant book of essays, Facing Up, took note of the changing landscape of physics at the end of the millennium. For the first time in history, physics had reached a dead end. A despair and a kind of “melancholy” had taken over the community of theoretical physicists. For the first time in history theory had outstripped experiment. The energy levels that were needed to help bring about the next big idea were from a technological perspective unimaginable. The billions or trillions of dollars, that are required — were unattainable. Moreover, Weinberg himself does not really “understand quantum mechanics” and cannot say with certainty if there will ever be a final theory.
Enter our two heroes, or anti-heroes: Peter Woit and Lee Smolin. They were both in the first string revolution right from the start. Jim Holt refers to them at this time (1984) as “journeyman physicists” — but given how young they were — I see them as beginners. Twenty years later (2006), although their paths were initially divergent, they would converge at a joint, radical position. They would embrace, each in their own way, a kind of David versus Goliath narrative — a narrative they recognized would be laughed at and ridiculed as a kind of opportunistic, look-at-me, attention-getting, Don Quixoteish tilting at windmills, cheap stunt. In two unexpected dark horse books, each would put forth, in the strongest terms possible, an emperor-has-no-clothes thesis: string theory is a “failed project” and is Not Even Wrong (Woit), and as a guiding paradigm is the root of just about everything that is sick about contemporary physics (The Trouble with Physics—Lee Smolin).
Of the two books, Holt clearly prefers Smolin’s. He finds it is considerably more lucid, more persuasive and thinks it’s better written. By comparison, Peter Woit’s book is really two books. The first book is a fairly standard textbook-treatment of quantum mechanics. It burdens its readers by unnecessary technical details and too many equations. The second half is where the book takes off, according to Holt. It is a movingly heartfelt, painstakingly honest chronicle of his struggles as a freshly minted PhD in theoretical physics, who, as an earnest post doc, finds out what happens when someone doesn’t play ball with the string establishment. Finding little that excites him in the string projects that his supervisors propose, and with no job prospects in sight Woit switched from physics to mathematics and never really looked back. Although he admires Woit for his intellectual honesty, Holt, who is not an easy critic to please, is compelled to note that there are “too many pages full of indigestible sentences like ‘The Hilbert space of the Wes-Zumino-Witten model is a representation not only of the Kac-Moody group, but the group of conformal representations as well.’”
Later when I would read Woit’s review of Holt’s review of his book I would be surprised to read that Woit — singling out his own notorious indigestible sentence — would be in full agreement with Holt that it was a totally horrible sentence. But not because he is just a bad writer but (for the nobler reason) that he was trying too hard to “introduce some higher math” for the benefit of his readers. It would be these two books Holt believes that would ignite what came to be called the “string wars.” Not because of their merits as books per se, but because of what they stood for. And what they stood for was, as mentioned, someone standing up and pointing out that the emperor has no clothes. That string theory is an intellectually bankrupt theory that has no experimental support whatsoever in over thirty years’ time. Holt concludes that time is running out for string theorists and they better come up with something pretty quick. To which Ed Witten, their indomitable leader retorts: “Why is thirty years too long a wait? What if it takes fifty years? If it’s right, and I think it is, it will be worth it.”
Later when I asked Woit why he thinks string theorists cannot concede the slightest failures, he shrugged, “well, they’ve invested so much, they’ve invested their lives in this… They don’t want to give it up.”
Yet, much as I agree with him and applaud his courageous stance against the reigning Goliath of the physics world (string theory) I wonder how he could be so certain that he is right and they are wrong.
I decide to ask.
“Ed Witten is the greatest string theorist in the world, right?”
He reflects for just a moment and nods.
“And Ed Witten is probably… no… he is the greatest string theorist who ever lived, right?”
Peter Woit nods his agreement, but he is looking at me in a quizzical way as though to say — where are you going with this?
“Well, do you ever think that Ed Witten then might be right in his views on string theory? And you might be wrong?”
Reacting as though this were a challenge and not a question, Woit stiffens in his chair and leans forward: “I AM VERY CONFIDENT that I AM RIGHT. No one has ever critiqued string theory with the level of detail that I have.”
He says it as authoritatively as LIGO scientists on February the 11th announced that Einstein’s prediction one hundred years ago that gravity waves exist had been experimentally confirmed. He says it with five sigma certainty. Except Peter Woit is not a LIGO experimental scientist who has spent much of his professional life fine tuning perhaps the most precise measuring apparatus — the laser interferometer observatory — in the history of physics. He is the senior lecturer in mathematics at Columbia trying to map out the interface between mathematics and quantum mechanics. He is, in other words, when it comes to theoretical physics a paper and pencil, back of the envelope, blackboard and eraser pure theorist.
Which suits me just fine, as I could not agree more with his conclusion. It’s just that his level of confidence, his five sigma certainty amazes me.
Jim Holt is one of my favorite writers, so I ask him what he thought of his review of his book.
“There were one or two things in it that weren’t right, but it was good…”
Conversationally, Peter Woit is a minimalist. No matter what I ask him, it takes him just a couple of seconds to come up with an answer. It takes him even less time to deliver the answer.
I tried to look on the bright side: at least I will get in a lot of questions (as anyone who knows me soon realizes, while I may not know the answer, I can always find the question).
I ask him if he knows Jim Holt, and he surprises me with a gratuitous little story:
“I met him once. He contacted me to ask if it would be okay to publish his review of my book, since it was scheduled to appear in advance of the publication date of my book. I said sure”
“What did you think of him?”
“I thought he was a nice guy.”
Although Lee Smolin and Peter Woit are often linked together — as principal drivers of what came to be called the string wars — I knew with hindsight that their trajectories since the publication of their twin assaults on the citadel of string theory, had considerably diverged. Woit moved further and further away from the landscape of ever proliferating string theories into the stratospheres of higher and higher mathematics; while Smolin, after writing 18 papers on string theory, abandoned the field and set out to carve his own niche. Subsequently, he would become one of the most innovative, if controversial physicists in the world. Along with Abhay Ashtekar, Carlo Rovelli and others he created—what is considered to be “our second best candidate for a quantum theory of gravity”— loop quantum gravity (LQG). He was the first to suggest the idea of a landscape of theories of physics, an idea snatched up by opportunistic string theorists such as Leonard Susskind. He was the first to suggest, in his famous book, The Life of the Cosmos, that the idea— that the cosmos is evolving – could help explain the origin of our universe.
It is a revolutionary model of cosmic origins about which world-class cosmologist, George Ellis (who in the 1960’s along with Stephen Hawking wrote the classic Large Scale Structure of the Universe) had this to say in 2016: “I think The Life of the Cosmos is of all the cosmological models on offer the best”
Peter Woit, for his part, does not lack admirers. None may be more important than professor Henry Pinkham, chairman of Columbia's math department, who admires Woit for being “the intellectual equal of the department's tenured faculty.” If you type his name under Amazon books and scroll down to reviewer's comments you will find (as I did) an extraordinary array of predominantly positive, sometimes glowing, comments from a broad range of readers.
I wonder (aloud) to what extent he considers Smolin an ally, a comrade in arms against the dragon, string theory.
For the first time, I detect a need to choose his words carefully:
“There are differences, you know, between us… especially now. I do think he did some really good work on loop quantum gravity… and he's a very clear writer…”
“Do you consider yourself a good writer… or someone who could become a good writer?”
Surprisingly, the question discourages Woit.
He shakes his head. “No.”
I don't know whether his lack of enthusiasm is aimed at the craft of writing in general or stems from a personal lack of confidence or lack of respect for the practical and aesthetic value of honing your writing skills.
Theoretical physicists, I know, vary greatly in their ability to express themselves. From Einstein, who you could count on to write beautifully no matter what he is saying. From Roger Penrose who was never less than elegant in his use of language; to Jeremy Bernstein, who is the only theoretical physicist I know (back in the day he worked side-by-side with Robert Oppenheimer and Murray Gell Mann) who also appears regularly in the New Yorker. To Richard Feynman, who received some of the worst English marks in the history of the Princeton graduate school entrance exams for prospective PhD candidates (while also receiving, some of the highest math and physics scores ever reported) yet amazingly became a best-selling popular author (Surely you're joking Mr. Feynman). Since there are few things I value more in the world (kindness and empathy are two of them) than good writing I cannot help asking myself what I really think of his writing style. And my conclusion is there must be a reason three years ago, out of a plethora of web-based physics blogs, I settled on Not Even Wrong. There must be a reason I follow it daily. There must be a reason I've read hundreds of his suggested links and once in a while even adopted one of his enthusiasms (e.g. the latest being Sabine Hossenfelder). And that reason is he has a certain roughhewn plain-spokenness that shines through. When you finish reading him, you have no doubt as to what he thinks. Over and over again he makes the same damning points: string theory, in every conceivable sense, has failed to deliver on its promises; its vaunted mathematical structure is “a gory mess;” after thirty years it is still “a failed project;” “instead of experiments it gives us excuses” (Feynman); it cannot point to a single prediction that has been experimentally validated. Reading Woit, you can see why his book (along with Smolin’s) struck a chord and became a lightning rod for “the string wars.”
So, yes, there is an undeniable roughhewn power to Woit’s writing. It takes talent to accomplish what he did. That said, although Woit clearly seems to appreciate what he considers good writing — it doesn’t seem to be something in which he's particularly interested. Which seems to be a reflection of the extraordinary isolationism and compartmentalization of contemporary physics: the narrowing focus and widening gap between rival specializations. Data, experimental results, theoretical proposals keep pouring in so fast, that unless you want to get left behind in the mad race towards a possible theory of everything, you must never look back.
That may be why when I ask Woit if he ever read Einstein's epoch making paper on the theory of General Relativity his answer is swift and sure. “No.” When I then ask him if he has ever read Einstein’s paper on Special Relativity, his answer is “No”. When I then ask him (not quite ready to give up) if he's ever read a single one of the 237 papers Einstein wrote in his lifetime, his answer is the same.
Before I can figure out a polite way to ask why, Woit, sensing my dismay leans forward and says, “You have to understand, I was obsessed with quantum mechanics, with the mystery of quantum mechanics.” I think Woit thinks, because I'm a psychotherapist, all you have to do is to reveal that you have a physics obsession and I will automatically know all I need to know about whatever drives him. Information, however, is not the same thing as understanding; but it’s an opening of sorts so I ask him what motivated him to get to where he's gotten?
For just a moment, he allows himself to become self reflective: “I was always a smart kid. A very smart kid. I suppose if I ever took a standardized test I would do very well, especially, in the area of abstract reasoning.”
Peter Woit says this as matter-of-factly as if he said, “When I was a kid my father drove a Chevrolet.” He says it as Kareem Abdul-Jabbar, if asked to describe how he became the person he is, might have said “I was always a tall kid. A very tall kid. In school, short kids bored me.”
I felt I had to say, “but there must be a few million people in the United States who would also score very high in abstract thinking in the standardized tests and none of them have your interests.”
“The people around here all do. And there are thousands of us all around the world.”
“But there are 7 billion people in the world.”
Peter Woit had to concede the mathematical point, but I don't think he appreciated the psychological distinction I was alluding to. There is an astonishing divide between the culture of science and the culture of humanities that C.P. Snow famously alluded to. There is even a greater divide between the culture of pure mathematics and the culture of the earthbound evolutionarily programmed biological world into which we are born.
There is a celebrated quip by Dick Cavett that encapsulates this. Reflecting on his famous interview of the then reigning world chess champion, Bobby Fischer, he observed:
“Throughout the interview I could feel the force of his two hundred IQ.”
Paraphrasing this I could say that throughout the interview, which was at times exhilarating, at times daunting, I could feel the force of his QMIQ (quantum mechanics IQ). Norman Mailer once commented that the immediacy of television — the fact that most influential people in the world can be brought into your living room — creates the illusion that you have thereby been included in their inner power circle, and to that extent vicariously empowered. But you are no closer to the corridors of power then you were before. Analogously, you can sit just a few feet away from a world-class expert, close enough to reach out and touch them, but you are no closer to their accumulated wisdom — unless you are willing to go home and put in ten thousand hours of hard work trying to raise the level of your understanding.
In Not Even Wrong Peter Woit relates an amazing story which illustrates the uniqueness of the mathematical mind. Woit, a graduate student at Princeton is walking up the stairway, thirty feet behind Ed Witten, who, disappears from view at the top of the stairway. When Woit himself reaches the top of the stairway, just seconds later, Witten has completely disappeared although the entrance to the nearest door was “quite a bit more than thirty feet.” It suddenly occurs to Woit that a “consistent explanation for everything was that Witten was an extraterrestrial being from a superior race who, since he thought no one was watching, had teleported back to his office.”
Woit seems uncomfortable when I bring this up. Although he acknowledges “the thought crossed his mind” he wants to minimize its importance, finally asserting, “it was a joke.”
Yet how different that is from the ordinary person. For the mathematical physicist, you need a million data points before you conclude (like at LIGO) that you have discovered something with a five sigma certainty. In the macroscopic world, you just need one data point, provided it is odd enough, spooky enough, and sufficiently memorable — and it can have a lasting profound effect on a person's life. Thus, I think about one of the first patients I ever saw who told me about the night he was lying in bed, and he felt another hand, a seemingly detached hand, holding his own hand for several minutes. I think of the man, just recently, getting up from his bed to go to the bathroom, who was startled by an “apparition.” Two ghostly figures silhouetted in multicolored lights dancing fifteen feet away in the foyer. Who, upon relaying the eerie experience to his wife is told that just yesterday morning she all of a sudden felt a strange “presence” behind her and then when she turned around, she felt whatever it was, had evaded her but was still watching her. As Oliver Sacks shows brilliantly in his book Hallucinations we are susceptible to hearing voices and seeing presences to a far greater extent than we imagine. To the non-mathematical mind, even the most transient thought of a premonition of a man being able to teleport himself through space-time — is a deeply unsettling occurrence (and hardly a joke.)
Which is to say that Peter Woit has a singular mind. I hope his new book on representation theory does well and that takes him to wherever he wants to go in the mathematical community that he seems to love. I think I can say when he decided to stand up to the dominating string theory establishment, to withstand the withering abuse of the troll-infested blogosphere and to follow his bliss instead — he made the right decision.
Glancing at my watch, I see that three and a half hours have passed. We have both have miles to go and promises to keep. So I stand up, shake hands and tell him how much I appreciate his generosity. Smiling, he says “it was fun.”
I hope so. I have a nagging fear that I was beginning to come across as the physics version of Lieutenant Colombo: just when you think I've stopped asking annoying questions, I think of another one. Nevertheless, I'm going to try to believe him.
So finally, to come full circle — who's winning the string wars? The short answer is no one. The longer answer is it’s a war no one can win. String theorists, Woit believes, have invested too much, they’re “going to go down fighting (Woit shakes his fist with mock bravura).” They are like the marines of physics. They never retreat. They just advance in different directions.
As for myself, although I have no skin in this war, I do have strong feelings. So at the top of my wish list is just this. I wish they would stop celebrating. I wish they would put the cork back in the champagne bottle. Put the champagne bottle back in the refrigerator and wait. Wait a year. A decade. A century. Wait until they make their first rock solid prediction, that is experimentally validated and stands the test of time. Then take the champagne bottle out of the refrigerator, pop the cork and let the celebration begin.
Readers who want to read more, see my new book, God and Therapy: What we believe when no one is watching (iBooks).
(Part I appeared on 2/23/16)
Published March 1st, 2016
Gerald Alper is an internationally recognized psychotherapist who is the author of 20 books. These include besides the celebrated Portrait Of The Artist As A Young Patient, The Paranoia Of Everyday Life, The Dark Side Of The Analytic Moon, The Puppeteers, The Elephant In The Room: The Denial of The Unconscious Mind, and more recently the just published God And Therapy: What We Believe When No One Is Watching (I Books, Alper). He's been a Fellow of The American Institute of Psychotherapy and Psychoanalysis since 1985, a reviewer for The Journal of Contemporary Psychology, a contributor of articles and essays to leading professional journals, a frequent guest author appearing on public access radio programs throughout the United States and Canada. His classic paper, A Psychoanalyist Takes the Turing Test, was included in the 2004 pioneering interdisciplinary anthology by Italian neuroscientist Franco Salzone who brought together seminal papers from both psychoanalysis and neuroscience. He lives with his wife in New York, stays in close contact with his two grown sons who remain hunkered down in Los Angeles and has been a practicing psychotherapist in Manhattan for the past 25 years.